Very low temperature refrigeration system having a scroll compressor with liquid injection

Abstract

Disclosed is a very low temperature or cryogenic refrigeration system with a scroll compressor and utilizing a mixed refrigerant that decreases refrigerant discharge temperature by refrigerant injection into the compressor.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is a continuation application of International Application PCT / US2003 / 029211 filed Sep. 18, 2003, now International Publication WO 2004 / 027324 and claims the benefit of U.S. Provisional application No. 60 / 411,676 filed Sep. 18, 2002, the contents of which are herein wholly incorporated by reference.BACKGROUND OF THE INVENTION[0002]Refrigeration systems have been in existence since the early 1900s, when reliable sealed refrigeration systems were developed. Since that time, improvements in refrigeration technology have proven their utility in both residential and industrial settings. In particular, very low temperature refrigeration systems currently provide essential industrial functions in biomedical applications, cryoelectronics, optical coating operations, industrial and commercial coating operations, and semiconductor manufacturing applications. Refrigeration systems manufacturers are also faced with increasingly restri...

AI Technical Summary

Benefits of technology

The present invention is a refrigeration system that uses a scroll compressor with liquid injection for cooling in a very low temperature range of -60°C to -208°C. This system is designed to improve efficiency and manage the discharge temperature of the compressor. By using a mixture of warm boiling and low boiling refrigerants, the system can achieve better cooling at lower temperatures. The scroll compressor is designed to manage the discharge temperature of the mixed refrigerant, ensuring higher concentrations of low boiling refrigerants without excess amounts accumulating in the compressor oil sump. The system also includes a high-capacity, compact scroll compressor that manages the discharge temperature of the mixed refrigerant containing low boiling refrigerants. The system is efficient, space-saving, and compatible with special low temperature oil.

Problems solved by technology

Refrigeration systems manufacturers are also faced with increasingly restrictive environmental regulations that have driven the refrigeration industry away from chlorinated fluorocarbons (CFCs) to hydrochlorinated fluorocarbons (HCFCs), and more recently, to hydrofluorocarbons (HFCs) due to a European Union law (in effect January 2001) banning use of HCFCs.

Semi-hermetic reciprocating compressors are particularly large, adding to the required floor space of a refrigeration system.

Steady state operation will typically be limited temperatures lower than 130° C. Temperatures in excess of 130° C. result in decomposition of the compressor oil and subsequent metal wear which results in a compressor failure.

In a typical unit, the discharge temperature of a scroll compressor imposes a significant limitation on the operating conditions of the compressor and reduces overall system efficiency.

Unfortunately, this system does not have a desirably high efficiency.

Unfortunately, this system does not have a desirably high efficiency.

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